Pipe fittings are used to connect sections of pipe. Stab-type fittings are a type of pipe fitting that is configured to be coupled to, for example inserted onto, an end of a pipe. One important aspect of pipe fittings is the ability to form an effective seal, for example an air tight seal, a water tight seal, or both an air and water tight seal.
Some pipe fittings include a seal member, for example an O-ring, which abuts an outer surface of the pipe and an inner surface of a portion of the pipe fitting. However, if the outer surface of the pipe is damaged, for example scratched, the seal member may not be capable of forming an effective seal with the section of the pipe.
Some pipe fittings include multiple seal members. Such a pipe fitting is described in International Publication No. 2004/063614, referred to herein as “WO 2004/063614.” In WO 2004/063614 a primary O-ring simultaneously engages the outer surface of the section of pipe and the inner surface of the sleeve of the pipe fitting, and a secondary O-ring that seals an outer surface of an insert of the pipe fitting against the inner surface of the sleeve.
After installation of a pipe fitting to the section of pipe as described in WO 2004/063614, loads applied to the section of pipe may result in bending of the pipe fitting, and the bending of the pipe fitting may result in a failure of the effective seal between the pipe fitting and the section of pipe.
Thus, a pipe fitting that is capable of forming an effective seal with a section of pipe, which may have external defects, and a pipe fitting that is further capable of maintaining the effective seal in the event of loads exerted on the section of pipe and the pipe fitting is desired.